#include <iostream>
#include <string>
using namespace std;

int height = 1;
class Screen {
public:
    typedef std::string::size_type pos;
    void dummy_fcn(pos height) {
        cout << height << endl;         // 访问形参 height 
        cout << this->height <<endl;    // 访问成员 height
        cout << Screen::height << endl; // 访问成员 height
        cout << ::height << endl;       // 访问全局 height
    }
private:
    pos height = 2;
};

int main() {
    Screen s;
    s.dummy_fcn(3);

    return 0;
}